Oxygen vacancies confined in nickel oxide nanoprisms arrays for promoted electrocatalytic water splitting
The water electrolysis, as a promising approach for producing clean hydrogen energy from water, has been considered as an efficient way to solve the energy crisis but is greatly limited by the energy climbing process of the hydrogen evolution reaction (HER). Hence, we designed a defect engineering method to synthesize NiO nanoprisms with abundant oxygen vacancy as a object of investigation to research the effect between oxygen vacancies and water splitting performance. Experimental results and theoretical calculation indicate that the NiO nanoprisms with abundant oxygen vacancy (b-NiO) shows excellent water splitting performance due to more exposed active area, enhanced conductivity, higher charge tranfer rate and higher adsorption energy of H2O molecules. Moreover, the b-NiO nanoprisms material requires a small cell voltage of 1.59 V to drive current density of 10 mA cm-2, which is lower than that of (1.70 V) pristine NiO (a-NiO). Our finding highlights significance of defect engineering to design highly activity materials as robust water splitting catalysts.